Motor drive device and air conditioner including the same

Abstract

The present application relates to a motor driving device and an air conditioner comprising the same. The motor driving device and the air conditioner comprising the same according to the embodiments of the present application, a switching device is arranged between a motor and an inverter, in a first wiring state of a winding of the motor, a first level of output current is output from the inverter, in a second wiring state of the winding of the motor, the first level of output current is output from the inverter. Thus, it can be determined whether the switching device for transforming the wiring of the motor is abnormal or not.

Description

TECHNICAL FIELD

[0001] The present application relates to a motor driving device and an air conditioner including the same, and more particularly, to a motor driving device capable of determining whether a switching device for transforming a connection of a motor is abnormal or not and an air conditioner including the same. BACKGROUND

[0002] An air conditioner is used to provide a more comfortable indoor environment by blowing cold or hot air into an indoor space, adjusting an indoor temperature, and purifying indoor air. Generally, an air conditioner includes an indoor unit configured of a heat exchanger and provided in an indoor space, and an outdoor unit configured of a compressor and a heat exchanger, which supplies a refrigerant to the indoor unit.

[0003] On the other hand, in order to improve power conversion efficiency or motor driving efficiency when a compressor motor is driven in a compressor, a switching device that transforms a winding of a motor into Y connection and Δ connection is disclosed in International Patent Application Publication WO19-008756 (hereinafter, referred to as “prior art document”).

[0004] However, according to the prior art document, in order to transform the winding of the motor into Y connection or Δ connection, a mechanical or electronic switch as the switching device is required, and such a switch can be damaged or have a reduced lifespan due to repeated use. SUMMARY

[0005] An object of the present application is to provide a motor driving device and an air conditioner including the same, which can determine whether a switching device for transforming a connection of a motor is abnormal or not.

[0006] Another object of the present application is to provide a motor driving device and an air conditioner including the same, which can determine whether the switching device is abnormal based on winding resistance under a first connection and winding resistance under a second connection according to an operation of the switching device.

[0007] Still another object of the present application is to provide a motor driving device and an air conditioner including the same, which can improve power conversion efficiency or motor driving efficiency when the switching device operates normally.

[0008] Still another object of the present application is to provide a motor driving device and an air conditioner including the same, which can make the switching device operate through one of a first connection and a second connection when the switching device is abnormal.

[0009] Still another object of the present application is to provide a motor driving device and an air conditioner including the same, which can determine whether a motor is malfunctioning or not.

[0010] A motor drive device and an air conditioner including the same according to an embodiment of the present application for achieving the above object include an inverter provided with a plurality of switching elements, which outputs an alternating current power to a motor based on switching operations; a switching device configured between the inverter and the motor, which changes a winding of the motor to a first wiring or a second wiring; an output current detection section for detecting an output current output from the inverter; and a control section which controls the inverter and the switching device, in a switching device check mode, during a first period, the winding of the motor is in a state of the first wiring according to an operation of the switching device, and a first level of the output current is output from the inverter, during a second period after the first period, the winding of the motor is in a state of the second wiring according to the operation of the switching device, and the first level of the output current is output from the inverter.

[0011] On the other hand, the control section can determine whether the switching device has an abnormal operation based on a winding resistance of the motor in the first wiring and a winding resistance of the motor in the second wiring.

[0012] On the other hand, the motor drive device and the air conditioner including the same according to an embodiment of the present application further include an output voltage detection section for detecting an output voltage output from the inverter, the control section can calculate a first winding resistance of the motor based on a first output voltage detected according to an output of the first level of the output current during the first period, the control section can calculate a second winding resistance of the motor based on a second output voltage detected according to an output of the first level of the output current during the second period, and the control section can determine whether the switching device has an abnormal operation based on the first winding resistance and the second winding resistance.

[0013] On the other hand, the control section can calculate a ratio of the first winding resistance and the second winding resistance, and can determine whether the switching device has an abnormal operation based on the calculated ratio.

[0014] On the other hand, the control section can calculate a ratio of the first winding resistance and the second winding resistance for each phase, can determine that the switching device is normal when the ratio of all of the phases in the calculated ratio is within a prescribed range, and can control such that the switching device changes the winding of the motor from the first wiring to the second wiring according to a rotation frequency of the motor.

[0015] On the other hand, the control section can control such that the motor continues to operate without being stopped during a period in which the switching device changes the winding of the motor from the first wiring to the second wiring.

[0016] On the other hand, the control section can control such that the rotation frequency of the motor decreases from a first frequency to a second frequency and then increases again during a period in which the switching device changes the winding of the motor from the first wiring to the second wiring.

[0017] On the other hand, the control section can calculate the ratio of the first winding resistance and the second winding resistance for each phase, determine that the switching device is abnormal when the ratio of at least one of the calculated ratios exceeds a prescribed range, and control so that the winding of the motor operates only in one of the first connection and the second connection.

[0018] On the other hand, the control section can calculate the first winding resistance and the second winding resistance for each phase, and determine that the motor is malfunctioning when the range of the first winding resistance for each phase exceeds a first range and the range of the second winding resistance for each phase exceeds a second range.

[0019] On the other hand, the control section can calculate the first winding resistance and the second winding resistance for each phase, and determine that the switching device is normal when the range of the first winding resistance for each phase is within a first range and the range of the second winding resistance for each phase is within a second range, and control so that the switching device switches the winding of the motor from the first connection to the second connection according to the operating frequency of the motor.

[0020] On the other hand, the control section can calculate the first winding resistance and the second winding resistance for each phase, and determine that the switching device is abnormal when the range of the first winding resistance for each phase is within a first range and the range of the second winding resistance for each phase exceeds a second range, and control so that the winding of the motor operates only in the first connection.

[0021] On the other hand, the control section can calculate the first winding resistance and the second winding resistance for each phase, and determine that the switching device is abnormal when the range of the first winding resistance for each phase exceeds a first range and the range of the second winding resistance for each phase is within a second range, and control so that the winding of the motor operates only in the second connection.

[0022] On the other hand, the control section can control so that, during a first period, the winding of the motor is in a first connection state, and the control section can control so that, during a second period, the winding of the motor is in a second connection state, and the control section can control so that, during the first period, the first level of output current and the second level of output current are sequentially output from the inverter with the winding of the motor in the first connection state, and the control section can control so that, during the second period, the first level of output current and the second level of output current are sequentially output from the inverter with the winding of the motor in the second connection state.

[0023] In another aspect, the motor driving device and the air conditioner including the same according to an embodiment of the present application further include an output voltage detection unit for detecting an output voltage output from the inverter, the control unit can calculate a first winding resistance of the motor based on the output voltage detected based on the output current of the first level and the second level during the first period, the control unit can calculate a second winding resistance of the motor based on a second output voltage detected based on the output current of the first level and the second level during the second period, and the control unit can determine whether the switching device is abnormally operated based on the first winding resistance and the second winding resistance.

[0024] In another aspect, the motor is a three-phase motor, the switching device includes first to third relay elements electrically connected to each phase output of the inverter, a first end of the first relay element, a first end of the second relay element, and a first end of the third relay element are connected in parallel, one end of a first winding of the motor is connected to a second end of the first relay element, one end of a second winding of the motor is connected to a second end of the second relay element, one end of a third winding of the motor is connected to a second end of the third relay element, the other end of the first winding of the motor is connected to a common end of the third relay element, the other end of the second winding of the motor is connected to a common end of the first relay element, and the other end of the third winding of the motor is connected to a common end of the second relay element.

[0025] In another aspect, the control unit controls the common ends of the first to third relay elements to be electrically connected to the first ends of the first to third relay elements to implement the first wiring, and the common ends of the first to third relay elements to be electrically connected to the second ends of the first to third relay elements to implement the second wiring.

[0026] In another aspect, the motor driving device and the air conditioner including the same according to an embodiment of the present application further include an output voltage detection unit for detecting an output voltage output from the inverter, the control unit can calculate a first winding resistance of the motor based on the output voltage detected based on the output current of the first level and the second level during the first period, the control unit can calculate a second winding resistance of the motor based on a second output voltage detected based on the output current of the first level and the second level during the second period, and the control unit can determine whether the switching device is abnormally operated based on the first winding resistance and the second winding resistance.

[0027] On the other hand, the control unit calculates the first winding resistance and the second winding resistance for each phase, determines that the switching device is abnormal when the range of the first winding resistance for each phase is within the first range and the range of the second winding resistance for each phase exceeds the second range, and controls the winding of the motor to operate only in the first connection, and determines that the switching device is abnormal when the range of the first winding resistance for each phase exceeds the first range and the range of the second winding resistance for each phase is within the second range, and can control the winding of the motor to operate only in the second connection.

[0028] On the other hand, the control unit calculates the first winding resistance and the second winding resistance for each phase, determines that the switching device is abnormal when the range of the first winding resistance for each phase is within the first range and the range of the second winding resistance for each phase exceeds the second range, and controls the winding of the motor to operate only in the first connection, and determines that the switching device is abnormal when the range of the first winding resistance for each phase exceeds the first range and the range of the second winding resistance for each phase is within the second range, and can control the winding of the motor to operate only in the second connection.

[0029] The motor driving device and the air conditioner including the same according to the embodiment of the present application, in which the switching device is provided between the motor and the inverter, in the switching device inspection mode, during a first period, the winding of the motor is in a state of the first connection according to the operation of the switching device, and the inverter outputs an output current of a first level, during a second period after the first period, the winding of the motor is in a state of the second connection according to the operation of the switching device, and the inverter outputs the output current of the first level. Thus, it can be determined whether the switching device for switching the connection of the motor is abnormal.

[0030] On the other hand, the control unit can determine whether the switching device operates abnormally based on the winding resistance of the motor in the first connection and the winding resistance of the motor in the second connection. Thus, based on the winding resistance in the first connection and the winding resistance in the second connection according to the operation of the switching device, it can be easily determined whether the switching device is abnormal.

[0031] On the other hand, the motor driving device and the air conditioner including the same according to the embodiment of the present application further include an output voltage detection unit for detecting an output voltage output from the inverter, the control unit can calculate the first winding resistance of the motor based on a first output voltage detected according to the output of the output current of the first level during the first period, the control unit can calculate the second winding resistance of the motor based on a second output voltage detected according to the output of the output current of the first level during the second period, and the control unit can determine whether the switching device operates abnormally based on the first winding resistance and the second winding resistance. Thus, it can be easily determined whether the switching device for switching the connection of the motor is abnormal.

[0032] On the other hand, the control section can calculate the ratio of the first winding resistance and the second winding resistance, and can determine whether the switching device is operating abnormally based on the calculated ratio. Thus, it is possible to easily determine whether the switching device that changes the wiring of the motor is operating abnormally.

[0033] On the other hand, the control section can calculate the ratio of the first winding resistance and the second winding resistance for each phase, and can determine that the switching device is normal when the ratio of all the phases in the calculated ratio is within a prescribed range, and the control section can control the switching device to change the winding of the motor from the first wiring to the second wiring in accordance with the operating frequency of the motor. Thus, it is possible to improve the power conversion efficiency or the motor drive efficiency when the switching device is operating normally.

[0034] On the other hand, the control section can control the motor to continue operating without stopping during the period in which the switching device changes the winding of the motor from the first wiring to the second wiring. As described above, since the motor does not stop when the switching device is performing the switching operation, it is possible to improve the operating efficiency of the motor.

[0035] On the other hand, the control section can control the motor to continue operating without stopping during the period in which the switching device changes the winding of the motor from the first wiring to the second wiring. As described above, since the motor does not stop when the switching device is performing the switching operation, it is possible to improve the operating efficiency of the motor.

[0036] On the other hand, the control section can calculate the ratio of the first winding resistance and the second winding resistance for each phase, and can determine that the switching device is abnormal when the ratio of at least one phase in the calculated ratio is outside a prescribed range, and the control section can control the winding of the motor to operate only in one of the first wiring and the second wiring. As described above, when the switching device is abnormal, it is possible to cause the motor to perform emergency operation by causing the switching device to operate only in one wiring state.

[0037] On the other hand, the control section can calculate the ratio of the first winding resistance and the second winding resistance for each phase, and can determine that the switching device is abnormal when the ratio of at least one phase in the calculated ratio is outside a prescribed range, and the control section can control the winding of the motor to operate only in one of the first wiring and the second wiring. As described above, when the switching device is abnormal, it is possible to cause the motor to perform emergency operation by causing the switching device to operate only in one wiring state.

[0038] On the other hand, the control section can calculate the ratio of the first winding resistance and the second winding resistance for each phase, and can determine that the switching device is abnormal when the ratio of at least one phase in the calculated ratio is outside a prescribed range, and the control section can control the winding of the motor to operate only in one of the first wiring and the second wiring. As described above, when the switching device is abnormal, it is possible to cause the motor to perform emergency operation by causing the switching device to operate only in one wiring state.

[0039] On the other hand, the control unit can calculate the first winding resistance and the second winding resistance for each phase, and when the range of the first winding resistance of each phase is within the first range and the range of the second winding resistance of each phase is outside the second range, the control unit can determine that the switching device is abnormal, and control the winding of the motor to operate only in the first connection. As described above, when the switching device is abnormal, the motor can be made to operate in an emergency by making the switching device operate only in one connection.

[0040] On the other hand, the control unit can calculate the first winding resistance and the second winding resistance for each phase, and when the range of the first winding resistance of each phase is outside the first range and the range of the second winding resistance of each phase is within the second range, the control unit can determine that the switching device is abnormal, and control the winding of the motor to operate only in the second connection. As described above, when the switching device is abnormal, the motor can be made to operate in an emergency by making the switching device operate only in one connection.

[0041] On the other hand, the control unit can control the winding of the motor to be in the first connection during the first period, and output the output current of the first level and the output current of the second level from the inverter in sequence, and the control unit can control the winding of the motor to be in the second connection during the second period, and output the output current of the first level and the output current of the second level from the inverter in sequence. As described above, since output currents of various levels are output, when determining whether the switching device for switching the connection of the motor is abnormal, the accuracy can be improved.

[0042] On the other hand, the motor driving device and the air conditioner including the device according to the embodiments of the present application further include an output voltage detection unit for detecting the output voltage output from the inverter, the control unit can calculate the first winding resistance of the motor based on the output voltage detected according to the output of the output current of the first level and the output current of the second level during the first period, the control unit can calculate the second winding resistance of the motor based on the second output voltage detected according to the output of the output current of the first level and the output current of the second level during the second period, and the control unit can determine whether the switching device operates abnormally based on the first winding resistance and the second winding resistance. Thus, based on the winding resistance under the first connection and the winding resistance under the second connection according to the operation of the switching device, it can be easily determined whether the switching device is abnormal.

[0043] In another aspect, the motor is a three-phase motor, the switching device includes first to third relay elements electrically connected to respective phase outputs of the inverter, first ends of the first to third relay elements are connected in parallel, one end of a first winding of the motor is connected to a second end of the first relay element, one end of a second winding of the motor is connected to a second end of the second relay element, one end of a third winding of the motor is connected to a second end of the third relay element, the other end of the first winding of the motor is connected to a common end of the third relay element, the other end of the second winding of the motor is connected to a common end of the first relay element, and the other end of the third winding of the motor is connected to a common end of the second relay element. Thus, the motor can be controlled by the switching device to operate in the first connection or the second connection, and the power conversion efficiency or the motor driving efficiency can be improved.

[0044] In another aspect, the control unit controls the common ends of the first to third relay elements to be electrically connected to the first ends of the first to third relay elements to realize the first connection, and controls the common ends of the first to third relay elements to be electrically connected to the second ends of the first to third relay elements to realize the second connection. Thus, the motor can be controlled by the switching device to operate in the first connection or the second connection, and the power conversion efficiency or the motor driving efficiency can be improved.

[0045] In another aspect, the motor driving device and the air conditioner including the device according to another embodiment of the present application include: an inverter provided with a plurality of switching elements, which outputs an alternating current power to a motor based on switching operations; a switching device configured between the inverter and the motor, which transforms windings of the motor into a first connection or a second connection; an output current detection unit for detecting an output current output from the inverter; and a control unit for controlling the inverter and the switching device, which determines whether the switching device abnormally operates based on a first winding resistance of the motor in the first connection and a second winding resistance of the motor in the second connection. Thus, whether the switching device abnormally operates can be easily determined based on the winding resistance in the first connection and the winding resistance in the second connection according to the operation of the switching device.

[0046] In another aspect, the control unit calculates the first winding resistance and the second winding resistance for each phase, determines that the motor is faulty when the range of the first winding resistance of each phase exceeds a first range and the range of the second winding resistance of each phase exceeds a second range, determines that the switching device is normal when the range of the first winding resistance of each phase is within the first range and the range of the second winding resistance of each phase is within the second range, and controls the switching device to transform the windings of the motor from the first connection to the second connection according to the operating frequency of the motor. Thus, whether the motor is faulty or the switching device is normal can be easily determined.

[0047] On the other hand, the control section calculates the first winding resistance and the second winding resistance for each phase, determines that the switching device is abnormal when the range of the first winding resistance for each phase is outside the first range and the range of the second winding resistance for each phase is within the second range, and controls the winding of the motor to operate only in the first connection. The control section determines that the switching device is abnormal when the range of the first winding resistance for each phase is within the first range and the range of the second winding resistance for each phase is outside the second range, and controls the winding of the motor to operate only in the second connection. As described above, when the switching device is abnormal, the motor can be operated in an emergency by causing the switching device to operate only in one connection. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 is a diagram illustrating the structure of an air conditioner according to an embodiment of the present application.

[0049] Figure 2 is a schematic diagram of an outdoor unit and an indoor unit of the air conditioner of Figure 1

[0050] Figure 3 is a schematic diagram of an indoor unit of the air conditioner of Figure 1

[0051] Figure 4 is an internal block diagram of a motor drive device according to an embodiment of the present application.

[0052] Figure 5 is an internal circuit diagram of the motor drive device of Figure 4

[0053] Figure 6 is an internal block diagram of an inverter control section of the motor drive device of Figure 5

[0054] is a diagram for explaining the operation of the switching device of Figure 7 Figure 4

[0055] Figure 8A and Figure 8B are timing charts illustrating the winding switching operation of the switching device of Figure 7

[0056] Figure 9A is a flowchart illustrating a method of operating the motor drive device according to an embodiment of the present application.

[0057] Figure 9B is a flowchart illustrating a method of operating the motor drive device according to another embodiment of the present application.

[0058] Figures 10A to 14C is a diagram for explaining the operation of the switching device of Figure 9A or Figure 9B ​​​​​​FIG. 1 is a flowchart illustrating an operation method of a motor driving apparatus according to an embodiment of the present application.

[0059] Figure 15 FIG. 2 is a flowchart illustrating an operation method of a motor driving apparatus according to another embodiment of the present application.

[0060] Figures 16A to 16C FIG. 3 is a flowchart illustrating an operation method of a motor driving apparatus according to another embodiment of the present application. Figure 15 DETAILED DESCRIPTION

[0061] Hereinafter, the present application will be described in detail with reference to the accompanying drawings.

[0062] In the following description, the suffix "module" or "part" of a structural element is given merely for the purpose of easy and clear description and does not have only the meaning of a special technical term or function. Therefore, it can be mixed and used with another "module" or "part".

[0063] Figure 1 FIG. 1 is a diagram illustrating a structure of an air conditioner according to an embodiment of the present application.

[0064] As shown in FIG. 1, the air conditioner according to the present application can include a plurality of indoor units 31, 32, 33, 34, 35, a plurality of outdoor units 21, 22 connected with the plurality of indoor units, a plurality of remote controllers 41, 42, 43, 44, 45 connected with the plurality of indoor units, respectively, and a remote controller 10 for controlling the plurality of indoor units and the plurality of outdoor units. Figure 1 The remote controller 10 is connected with the plurality of indoor units 31, 32, 33, 34, 35 and the plurality of outdoor units 21, 22 and monitors and controls operations thereof. At this time, the remote controller 10 can be connected with the plurality of indoor units and perform operation setting, lock setting, schedule control, group control, etc. of the indoor units.

[0065] The air conditioner 100 can be applied to any one of a floor standing type air conditioner, a wall mounted type air conditioner, and a ceiling mounted type air conditioner, but for convenience of explanation, hereinafter, the ceiling mounted type air conditioner will be described as an example.

[0066] In addition, the air conditioner can further include at least one of a ventilation device, an air purifying device, a humidifying device, and a heater, and can operate in conjunction with operations of the indoor units and the outdoor units.

[0067]

[0068] ​​The outdoor units 21, 22 include a compressor (not shown) that receives refrigerant and compresses it, an outdoor heat exchanger (not shown) that exchanges heat between refrigerant and outdoor air, a receiver (not shown) that extracts gaseous refrigerant from supplied refrigerant and supplies it to the compressor, and a four-way valve (not shown) that selects a flow path of refrigerant according to heating operation. In addition, a plurality of sensors, valves, and an oil separator, etc. are included, but the description of the structure thereof will be omitted in the following.

[0069] The outdoor units 21, 22 operate the compressor and the outdoor heat exchanger possessed thereby, compress or exchange heat of refrigerant according to settings, and supply refrigerant to the indoor units 31, 32, 33, 34, 35. The outdoor units 21, 22 are driven according to a request from the remote controller 10 or the indoor units 31, 32, 33, 34, 35, and as the refrigeration / heating capacity changes in correspondence with the driven indoor unit, the number of operations of the outdoor unit and the number of operations of the compressor provided in the outdoor unit change.

[0070] At this time, the outdoor units 21, 22 are described by way of example in which a plurality of outdoor units supply refrigerant to the respective indoor units connected thereto, but the plurality of outdoor units can be connected to each other and supply refrigerant to a plurality of indoor units according to the connection structure of the outdoor units and the indoor units.

[0071] The indoor units 31, 32, 33, 34, 35 are connected to any one of the plurality of outdoor units 21, 22, and receive refrigerant to discharge cool or warm air into a room. The indoor units 31, 32, 33, 34, 35 include an indoor heat exchanger (not shown), an indoor unit fan (not shown), an expansion valve (not shown) for expanding supplied refrigerant, and a plurality of sensors (not shown).

[0072] At this time, the outdoor units 21, 22 and the indoor units 31, 32, 33, 34, 35 are connected by a communication line and transmit / receive data to / from each other, and the outdoor units and the indoor units are connected to the remote controller 10 by a separate communication line and operate according to control of the remote controller 10.

[0073] The remote controllers 41, 42, 43, 44, 45 can be connected to the indoor units, respectively, and input a user's control instruction to the indoor units, and receive and display status information of the indoor units. At this time, the remote controllers can communicate in a wired or wireless manner according to the connection form with the indoor units, and a plurality of indoor units can be connected to one remote controller, and the settings of the plurality of indoor units can be changed by input of one remote controller, according to circumstances.

[0074] In addition, the remote controllers 41, 42, 43, 44, 45 can include a temperature detection sensor inside.

[0075] Figure 2 isFigure 1 a schematic view of an outdoor unit and an indoor unit.

[0076] Referring to the drawings, an air conditioner 100 is generally divided into an indoor unit 31 and an outdoor unit 21.

[0077] The outdoor unit 21 includes a compressor 102 to function as compressing a refrigerant, a compressor motor 102b to drive the compressor, an outdoor heat exchanger 104 to function as radiating the compressed refrigerant, an outdoor blower 105 disposed at one side of the outdoor heat exchanger 104, which is composed of an outdoor fan 105a to facilitate the radiation of the refrigerant and a motor 105b to rotate the outdoor fan 105a, an expansion mechanism 106 to expand the condensed refrigerant, a cooling / heating switching valve 110 to change a flow path of the compressed refrigerant, and a receiver 103 to temporarily store the vaporized refrigerant and supply the refrigerant of a predetermined pressure to the compressor after removing moisture and foreign matters.

[0078] The indoor unit 31 includes an indoor heat exchanger 108 to be disposed in the indoor and perform a cooling / heating function, and an indoor blower 109 disposed at one side of the indoor heat exchanger 108, which is composed of an indoor fan 109a to facilitate the radiation of the refrigerant and a motor 109b to rotate the indoor fan 109a.

[0079] The indoor heat exchanger 108 can be provided with at least one. The compressor 102 can use at least one of a variable frequency compressor and a constant speed compressor.

[0080] In addition, the air conditioner 100 can be composed of a cooling mechanism to cool the indoor, or a heat pump to cool or heat the indoor.

[0081] On the other hand, Figure 2 One indoor unit 31 and one outdoor unit 21 are shown, but the driving apparatus of the air conditioner according to the embodiment of the present application is not limited thereto, and it is obvious that it can be applied to a multi-type air conditioner having a plurality of indoor units and outdoor units, an air conditioner having one indoor unit and a plurality of outdoor units, etc.

[0082] Figure 1 The compressor 102 in the outdoor unit 21 can be driven by a motor driving apparatus 220 to drive the compressor motor 230.

[0083] Figure 3 is Figure 1 a brief internal block diagram of the air conditioner.

[0084] Referring to the drawings, Figure 3The air conditioner 100 includes a compressor 102, an outdoor fan 105a, an indoor fan 109a, a control section 170, a discharge temperature detecting section 118, an outdoor temperature detecting section 138, an indoor temperature detecting section 158, and a storage 140.

[0085] In addition, the air conditioner 100 can further include a compressor driving section 220, an outdoor fan driving section 200, an indoor fan driving section 300, a switching valve 110, an expansion valve 106, a display section 130, and an input section 120.

[0086] Regarding the compressor 102, the outdoor fan 105a, and the indoor fan 109a, refer to Figure 2 .

[0087] The input section 120 is provided with a plurality of operation buttons, and transmits a signal inputted with respect to an operation target temperature of the air conditioner 100 to the control section 170.

[0088] The display section 130 can display an operation state of the air conditioner 100.

[0089] The storage 140 can store data required for the operation of the air conditioner 100.

[0090] The discharge temperature detecting section 118 can detect a refrigerant discharge temperature Tc in the compressor 102, and can transmit a signal corresponding to the detected refrigerant discharge temperature Tc to the control section 170.

[0091] The outdoor temperature detecting section 138 can detect a temperature around the outdoor unit 21 of the air conditioner 100, that is, an outdoor temperature To, and can transmit a signal corresponding to the detected outdoor temperature To to the control section 170.

[0092] The indoor temperature detecting section 158 can detect a temperature around the indoor unit 31 of the air conditioner 100, that is, an indoor temperature Ti, and can transmit a signal corresponding to the detected indoor temperature Ti to the control section 170.

[0093] The control section 170 can control the operation of the air conditioner 100 based on at least one of the detected refrigerant discharge temperature Tc, the detected outdoor temperature To, the detected indoor temperature Ti, and the input target temperature. For example, a final target superheat degree can be calculated, and the operation of the air conditioner 100 can be controlled.

[0094] On the other hand, as illustrated, in order to control the operation of the compressor 102, the indoor fan 109a, and the outdoor fan 105a, the control section 170 can control the compressor driving section 220, the outdoor fan driving section 200, and the indoor fan driving section 300, respectively.

[0095] For example, the control portion 170 can output respective speed command value signals to the compressor driving portion 220, the outdoor fan driving portion 200, or the indoor fan driving portion 300, respectively, based on the target temperature.

[0096] Also, the compressor motor (102b), the outdoor blower motor (105b), and the indoor blower motor (109b) can operate at target rotational speeds, respectively, based on respective speed command value signals.

[0097] On the other hand, the control portion 170 can control the operation of the air conditioner 100 as a whole, in addition to the compressor driving portion 220, the outdoor fan driving portion 200, or the indoor fan driving portion 300.

[0098] For example, the control portion 170 can control the operation of the refrigeration / heating switching valve 110 or the four-way valve.

[0099] Alternatively, the control portion 170 can control the operation of the expansion mechanism or the expansion valve 106.

[0100] Figure 4 FIG. 1 is a diagram showing an example of an internal block diagram of a motor driving apparatus according to an embodiment of the present application, Figure 5 Figure 4

[0101] Referring to the drawings, the motor driving apparatus 220 according to an embodiment of the present application is used to drive a motor in a sensorless manner, and can be referred to as a power conversion apparatus.

[0102] The motor driving apparatus 220 according to an embodiment of the present application can include a converter 410, an inverter 420, an inverter control portion 430, a switching device 450, a dc terminal voltage detection portion B, a dc terminal capacitor C, an output current detection portion E, and an output voltage detection portion F. In addition, the motor driving apparatus 220 can further include an input current detection portion A, and the like.

[0103] The input current detection portion A can detect an input current i s To this end, as the input current detection portion A, a CT (current transformer), a shunt resistor, or the like can be used. The detected input current i s As a discrete signal of a pulse pattern, the detected input current i

[0104] ​​The converter 410 converts the commercial AC power source 405 that has passed through the reactor L into a DC power source and outputs it. In the drawing, the commercial AC power source 405 is shown as a three-phase AC power source, but it can also be a single-phase AC power source. Depending on the kind of the commercial AC power source 405, the internal structure of the converter 410 will also be different.

[0105] On the other hand, the converter 410 is configured from diodes and the like, and does not have switching elements, so that it can perform a rectification action without an additional switching action.

[0106] For example, in the case of a three-phase AC power source, the converter 410 can have six diodes in a bridge configuration, and in the case of a single-phase AC power source, the converter 410 can have four diodes in a bridge configuration.

[0107] On the other hand, in the case of a three-phase AC power source, the converter 410 can have six switching elements and six diodes, and in the case of a single-phase AC power source, the converter 410 can also be a half-bridge type converter that has two switching elements and four diodes.

[0108] In the case where the converter 410 has switching elements, by the switching action of the corresponding switching elements, it is possible to perform a step-up action, power factor improvement, and DC power source conversion.

[0109] The dc terminal capacitor C is disposed at the dc terminal, and stores the power source output from the converter 410. In the drawing, one element is exemplified as the dc terminal capacitor C, but a plurality of elements can also be provided to ensure element stability.

[0110] On the other hand, in the drawing, an example is shown in which the output terminal of the converter 410 is connected, but it is not limited to this, and the DC power source can also be input directly.

[0111] For example, the DC power source from a solar cell can be input directly to the dc terminal capacitor C, or it can also be input after being converted from DC to DC. Hereinafter, the description will be made mainly with respect to the part exemplified in the drawing.

[0112] On the other hand, the dc terminal capacitor C stores a DC power source across its terminals, so it can be referred to as a dc terminal or a dc link terminal.

[0113] The dc terminal voltage detection section B can detect the dc terminal voltage Vdc across the dc terminal capacitor C. To do so, the dc terminal voltage detection section B can include a resistance element, an amplifier, and the like. The detected dc terminal voltage Vdc is a discrete signal in a pulse form, and can be input to the inverter control section 430.

[0114] The inverter 420 can be provided with a plurality of inverter switching elements Sa to Sc, S'a to S'c, and by on / off operation of the switching elements, a direct-current power source Vdc of the dc terminal is converted into a three-phase alternating-current power source va, vb, vc, and output to the three-phase synchronous motor 230.

[0115] In the inverter 420, the upper arm switching elements Sa, Sb, Sc and the lower arm switching elements S'a, S'b, S'c, which are connected in series with each other, respectively, become a pair, and in total, three pairs of upper arm and lower arm switching elements are connected in parallel with each other (Sa & S'a, Sb & S'b, Sc & S'c). In each of the switching elements Sa, S'a, Sb, S'b, Sc, S'c, a diode is connected in anti-parallel.

[0116] The plurality of switching elements in the inverter 420 cause each of the switching elements to perform on / off operation based on an inverter switching control signal Sic from the inverter control section 430. Thereby, a three-phase alternating-current power source having a prescribed frequency is output to the three-phase synchronous motor 230.

[0117] The inverter control section 430 can control the switching operation of the inverter 420 based on a sensorless method. To this end, the inverter control section 430 can receive an output current io detected in the output current detection section E.

[0118] In order to control the switching operation of the inverter 420, the inverter control section 430 outputs an inverter switching control signal Sic to the inverter 420. The inverter switching control signal Sic is a pulse width modulation (PWM) type switching control signal, which is generated and output based on the output current io detected in the output current detection section E. Details of the output of the inverter switching control signal Sic in the inverter control section 430 will be described later. Figure 6

[0119] The output current detection section E detects an output current io flowing between the inverter 420 and the three-phase motor 230. That is, the current flowing in the motor 230 is detected. The output current detection section E can detect the output currents ia, ib, ic of all phases, or can also detect the output currents of two phases using three-phase balance.

[0120] The output current detection section E can be located between the inverter 420 and the motor 230, and in order to perform current detection, a CT (current transformer), a shunt resistor, or the like can be used.

[0121] In the case of using a shunt resistor, three shunt resistors can be located between the inverter 420 and the synchronous motor 230, or one end of each of the three shunt resistors can be connected to the three lower arm switching elements S'a, S'b, S'c of the inverter 420, respectively.​

[0122] On the other hand, two shunt resistors can be used with three-phase balance. On the other hand, in the case of using one shunt resistor, a corresponding shunt resistor can be arranged between the above-mentioned capacitor C and the inverter 420.

[0123] The detected output current io is a discrete signal in a pulse form, and can be applied to the inverter control section 430, and an inverter switching control signal Sic is generated based on the detected output current io. Hereinafter, the detected output current io can also be described in parallel as output currents ia, ib, and ic of three phases.

[0124] The output voltage detection section F can detect an output voltage vo output from the inverter 420. Specifically, output voltages vo of respective phases output from the inverter 420 can be detected. To this end, the output voltage detection section F can include a resistance element, an amplifier, and the like. The detected output voltage vo is a discrete signal in a pulse form, and can be input to the inverter control section 430.

[0125] On the other hand, the three-phase motor 230 is provided with a stator and a rotor, and the rotor is rotated by applying an alternating current power of a predetermined frequency to a coil of the stator of each phase (a phase, a b phase, and a c phase).

[0126] Such a motor 230 can include, for example, a surface-mounted permanent magnet synchronous motor (SMPMSM), an interior permanent magnet synchronous motor (IPMSM), and a synchronous reluctance motor (Synrm), and the like. Among them, the SMPMSM and the IPMSM are permanent magnet synchronous motors (PMSM), and the Synrm is characterized by not having a permanent magnet.

[0127] On the other hand, the switching device 450 can be arranged between the inverter 420 and the motor 230, and can convert a winding of the motor 230 to a first connection or a second connection.

[0128] Here, the first connection can mean a Y connection, and the second connection can be a Δ connection.

[0129] To this end, the switching device 450 can include three relay elements SW1, SW2, SW3 connected between the three-phase output of the inverter 420 and the three-phase coils CA, CB, CC of the motor 230, respectively.

[0130] That is, the switching device 450 can include a first relay element SW1, a second relay element SW2, and a third relay element SW3 electrically connected to each phase output.

[0131] In a case where the motor 230 is below a first speed or a first operating frequency, the switching device 450 can operate to place the motor 230 in the first wiring, and in a case where the motor 230 exceeds the first speed or the first operating frequency, the switching device 450 can operate to place the motor 230 in the second wiring. Thereby, power conversion efficiency or motor driving efficiency can be improved.

[0132] In particular, power conversion efficiency or motor driving efficiency at a low speed below the first speed or the first operating frequency can be improved.

[0133] On the other hand, the motor driving device 220 of the embodiment of the present application includes: an inverter 420 provided with a plurality of switching elements Sa~Sc, S'a~S'c, which outputs an alternating current power to a motor 230 based on switching operation; a switching device 450 disposed between the inverter 420 and the motor 230, which transforms a winding of the motor 230 into a first wiring or a second wiring; an output current detection section E for detecting an output current io output from the inverter 420; and a control section 170 or an inverter control section 430 for controlling the inverter 420 and the switching device 450, in a switching device 450 check mode, during a first period Pn1, the winding of the motor 230 is in a first wiring state according to operation of the switching device 450, and an output current io of a first level Lvn1 is output from the inverter 420, during a second period Pn2 after the first period Pn1, the winding of the motor 230 is in a second wiring state according to operation of the switching device 450, and an output current io of the first level Lvn1 is output from the inverter 420. Thereby, it is possible to determine whether the switching device 450 for transforming the wiring of the motor 230 is abnormal or not. For this, reference will be made to Figure 7 The following will be described in detail.

[0134] Figure 6 is Figure 5 an internal block diagram of the inverter control section.

[0135] Referring to Figure 6 , the inverter control section 430 can include a shaft conversion section 310, a speed calculation section 320, a current command generation section 330, a voltage command generation section 340, a shaft conversion section 350, and a switching control signal output section 360.

[0136] The axis conversion unit 310 receives the three-phase output currents ia, ib, and ic detected by the output current detection unit E and converts them into two-phase currents iα and iβ in a stationary coordinate system.

[0137] On the other hand, the axis conversion unit 310 can convert the two-phase currents iα and iβ in the stationary coordinate system into the two-phase currents id and iq in the rotating coordinate system.

[0138] The speed calculation unit 320 can output the calculated position based on the two-phase currents iα and iβ of the stationary coordinate system axis-converted by the axis conversion unit 310. and the calculated speed

[0139] On the other hand, the current command generating unit 330 is based on the calculation speed and speed command value ω * r , generate current command value i * q For example, the current command generating unit 330 may be based on the operation speed and speed command value ω * r The PI controller 335 performs PI control and can generate a current command value i * q In the drawings, although the current command value is shown as the q-axis current command value i * q , but unlike the attached figure, the d-axis current command value i can also be generated together * d On the other hand, the d-axis current command value i * d The value of is set to 0.

[0140] On the other hand, the current command generating unit 330 may further include a limiter (not shown) for limiting its level to prevent the current command value i * q Exceeds the allowed range.

[0141] Next, the voltage command generating unit 340 generates the voltage command based on the d-axis and q-axis currents i i that have been converted into the two-phase rotating coordinate system by the axis conversion unit. d 、i q and the current command value i from the current command generating unit 330 and the like. * d 、i * q To generate the d-axis and q-axis voltage command values ​​v * d 、v * qFor example, the voltage command generation section 340 can execute PI control in a PI controller 344 based on the difference between the q-axis current i q and the q-axis current command value i * and generate the q-axis voltage command value v q * q In addition, the voltage command generation section 340 can execute PI control in a PI controller 348 based on the difference between the d-axis current i d and the d-axis current command value i * d and generate the d-axis voltage command value v * d On the other hand, the voltage command generation section 340 can also be provided with a limiter (not shown) for limiting the level thereof to prevent the d-axis, q-axis voltage command values v * d , v * q from exceeding the allowable range.

[0142] On the other hand, the generated d-axis, q-axis voltage command values v * d , v * q are input to an axis conversion section 350.

[0143] The axis conversion section 350 receives the position calculated in the speed calculation section 320 and the d-axis, q-axis voltage command values v * d , v * q and performs axis conversion.

[0144] First, the axis conversion section 350 performs conversion from the two-phase rotating coordinate system to the two-phase stationary coordinate system. At this time, the position

[0145] calculated in the speed calculation section 320 can be used. Further, the axis conversion section 350 performs conversion from the two-phase stationary coordinate system to the three-phase stationary coordinate system. Through this conversion, the axis conversion section 350 outputs the three-phase output voltage command values v * a, v * b, v * c.

[0146] The switching control signal output section 360 generates and outputs an inverter-use switching control signal Sic in a pulse width modulation (PWM) manner based on the three-phase output voltage command values v * a, v * b, v * c.

[0147] The output inverter switching control signal Sic can be converted into a gate drive signal in a gate drive section (not shown) and can be input to the gate of each switching element within the inverter 420. Thereby, each switching element Sa, S'a, Sb, S'b, Sc, S'c within the inverter 420 performs a switching operation.

[0148] On the other hand, as described above, the motor drive device 220 must detect the output current io flowing in the motor, particularly the phase current, to perform vector control for driving the motor 230 by the inverter 420 control.

[0149] The inverter control section 430 can control the motor 230 at a desired speed and torque using the detected phase current and using the current command generation section 330, the voltage command generation section 340.

[0150] Figure 7 is a diagram referred to when describing the operation of the switching device of Figure 4 Fig. 2 is a diagram referred to when describing the operation of the switching device of

[0151] Referring to the drawings, Figure 7 (a) of Fig. 1 illustrates the operation of the motor 230 as the Y connection according to the operation of the switching device 450, Figure 7 (b) of Fig. 1 illustrates the operation of the motor 230 as the Δ connection according to the operation of the switching device 450.

[0152] The switching device 450 includes a first relay element SW1, a second relay element SW2, and a third relay element SW3 electrically connected to each phase of the inverter 420.

[0153] The first end naa of the first relay element SW1, the first end nba of the second relay element SW2, and the first end nca of the third relay element SW3 are connected in parallel, one end nA of the first winding CA of the motor 230 is connected to the second end nab of the first relay element SW1, one end nB of the second winding CB of the motor 230 is connected to the second end nbb of the second relay element SW2, one end nC of the third winding CC of the motor 230 is connected to the second end ncb of the third relay element SW3, the other end na of the first winding CA of the motor 230 is connected to the common end n3 of the third relay element SW3, the other end nb of the second winding CB of the motor 230 is connected to the common end n1 of the first relay element SW1, and the other end nc of the third winding CC of the motor 230 is connected to the common end n2 of the second relay element SW2.

[0154] On the other hand, the second end nab of the first relay element SW1 is connected to the u-phase output terminal ru of the inverter 420, the second end nbb of the second relay element SW2 is connected to the v-phase output terminal rv of the inverter 420, and the second end ncb of the third relay element SW3 is connected to the w-phase output terminal rw of the inverter 420.

[0155] As shown in (a) of FIG. 10, Figure 7 The control section 170 or the inverter control section 430 can control the common terminals nl, n2, n3 of the first relay element SW1, the second relay element SW2, the third relay element SW3 to be electrically connected to the first terminals naa, nba, nca of the first relay element SW1, the second relay element SW2, the third relay element SW3, respectively, to realize the first wiring.

[0156] Thus, the output currents of the u, v, w phases of the inverter 420 flow in the respective a-phase coils CA, b-phase coils CB, c-phase coils CC in the motor 230 in the Y wiring.

[0157] As shown in (b) of FIG. 10, Figure 7 The control section 170 or the inverter control section 430 can control the common terminals nl, n2, n3 of the first relay element SW1, the second relay element SW2, the third relay element SW3 to be electrically connected to the second terminals nab, nbb, ncb of the first relay element SW1, the second relay element SW2, the third relay element SW3, respectively, to realize the second wiring.

[0158] Thus, the output currents of the u, v, w phases of the inverter 420 flow in the respective b-phase coils CB, c-phase coils CC, a-phase coils CA in the motor 230 in the Δ wiring.

[0159] As a result, the motor 230 can be controlled to be in the first wiring or the second wiring operation by the switching device 450, and further, the power conversion efficiency or the motor 230 driving efficiency can be improved.

[0160] Figure 8A and Figure 8B is a timing chart showing the winding switching operation of the switching device of Figure 7

[0161] First, Figure 8A is a timing chart showing an example of the winding switching operation of the switching device.

[0162] Referring to the drawings, in a case where the operating frequency of the motor 230 is f1 or less, as shown in (a) of FIG. 11, the switching device 450 can operate to cause the motor 230 to be in the Y wiring state. Figure 7

[0163] ​​In the drawing, it is illustrated that the switching device 450 is operated so that the motor 230 is in the Y connection state during a P1x period until a Txa time point.

[0164] Next, the motor 230 can be stopped during a Px period between the Txa time point and a Txb time point.

[0165] Then, as shown in (b) of FIG. 10, the switching device 450 can be operated so that the motor 230 is in the Δ connection state during a P2x period after the Txb time point. Figure 7

[0166] For example, in a case where the operating frequency of the motor 230 exceeds f1, the switching device 450 is operated so that the motor 230 is in the Δ connection state, and the motor 230 can be stopped during the Px period to change from the Y connection to the Δ connection.

[0167] Next, Figure 8B is a timing chart illustrating another example of the winding switching operation of the switching device.

[0168] Referring to the drawing, in a case where the operating frequency of the motor 230 is f1 or less, as shown in (b) of FIG. 11, the switching device 450 can be operated so that the motor 230 is in the Y connection state. Figure 7

[0169] In the drawing, it is illustrated that the switching device 450 is operated so that the motor 230 is in the Y connection state during a P1 period until a Ta time point.

[0170] Next, the control section 170 or the inverter control section 430 can control the winding of the motor 230 to change from the first connection to the second connection during a P2 period between the Ta time point and a Tb time point.

[0171] In particular, the control section 170 or the inverter control section 430 can be controlled so that the motor 230 is not stopped during the P2 period, and the operating frequency of the motor 230 is temporarily decreased from the first frequency f1 to the second frequency f2.

[0172] Then, as shown in (b) of FIG. 12, the switching device 450 can be operated so that the motor 230 is in the Δ connection state during a P3 period after the Tb time point. Figure 7

[0173] For example, the control section 170 or the inverter control section 430 can be controlled so that, in a case where the operating frequency of the motor 230 exceeds f1, the switching device 450 is operated so that the motor 230 is in the Δ connection state.

[0174] ​​​Specifically, the control section 170 or the inverter control section 430 can be controlled to cause the operating frequency of the motor 230 temporarily lowered to the second frequency f2 to be raised again during the P3 period.

[0175] The control section 170 or the inverter control section 430 can be controlled to cause the motor 230 to continue to operate without stopping during the period in which the switching device 450 changes the winding of the motor 230 from the first connection to the second connection. As described above, since the motor 230 does not stop when the switching device 450 performs the switching operation, the operating efficiency of the motor 230 can be improved.

[0176] On the other hand, preferably, Figure 8B the P2 period is shorter than Figure 8A the Px period. Thereby, the winding of the motor 230 can be changed from the first connection to the second connection while temporarily lowering the speed of the motor 230.

[0177] Figure 9A is a flowchart showing a method of operating the motor drive device according to an embodiment of the present application.

[0178] Referring to the drawings, the control section 170 or the inverter control section 430 determines whether the motor drive device 220 is in the switching device check mode (S910).

[0179] For example, the control section 170 or the inverter control section 430 can be controlled to perform the switching device check mode before driving the motor 230.

[0180] As another example, the control section 170 or the inverter control section 430 can be controlled to perform the switching device check mode when the change in the operating frequency is equal to or greater than a predetermined value in the driving of the motor 230.

[0181] The control section 170 or the inverter control section 430 is controlled to, in the switching device check mode, cause the winding of the motor 230 to be in the first connection state according to the operation of the switching device 450 and cause the inverter 420 to output the first level of output current during the first period (S920).

[0182] Next, the control section 170 or the inverter control section 430 is controlled to, in the switching device check mode, cause the winding of the motor 230 to be in the second connection state according to the operation of the switching device 450 and cause the inverter 420 to output the first level of output current, which is the same as the first connection state, during the second period after the first period (S930).

[0183] Then, the control section 170 or the inverter control section 430 determines whether the switching device 450 has abnormal operation based on the winding resistance of the motor 230 in the first connection and the winding resistance of the motor 230 in the second connection (S940).

[0184] For example, the control section 170 or the inverter control section 430 can calculate the first winding resistance of the motor 230 based on the first output voltage Lvn3 detected from the output of the output current io of the first level Lvn1 during the first period Pn1, can calculate the second winding resistance of the motor 230 based on the second output voltage Lvn4 detected from the output of the output current io of the first level Lvn1 during the second period Pn2, and can determine whether the switching device 450 is abnormally operated based on the first winding resistance and the second winding resistance. Thereby, it is possible to easily determine whether the switching device 450 for switching the wiring of the motor 230 is abnormal.

[0185] Specifically, the control section 170 or the inverter control section 430 can calculate the ratio of the first winding resistance and the second winding resistance and determine whether the switching device 450 is abnormally operated based on the calculated ratio. Thereby, it is possible to easily determine whether the switching device 450 for switching the wiring of the motor 230 is abnormal.

[0186] On the other hand, the control section 170 or the inverter control section 430 can be controlled to calculate the ratio of the first winding resistance and the second winding resistance for each phase, determine that the switching device 450 is normal if the ratio of all phases in the calculated ratio is within a prescribed range, and cause the switching device 450 to switch the winding of the motor 230 from the first wiring to the second wiring according to the operating frequency of the motor 230. Thereby, in the case where the switching device 450 is normally operated, it is possible to improve the power conversion efficiency or the motor 230 driving efficiency.

[0187] Figure 9B is a flowchart showing an operation method of a motor driving device according to another embodiment of the present application.

[0188] Referring to the drawings, Figure 9B The operation method of Figure 9A is similar to the operation method of

[0189] The description of the steps S910, S920, S930, and S940 is referred to the description of the steps S910, S920, S930, and S940 of Figure 9A

[0190] In the step S920, the control section 170 or the inverter control section 430 is controlled to cause the inverter 420 to output the output current of the first level during the first period in the switching device check mode with the winding of the motor 230 in the first wiring state according to the operation of the switching device 450.

[0191] ​Next, the control section 170 or the inverter control section 430 controls so that, during the first period, the winding of the motor 230 is in the first wiring state according to the operation of the switching device 450, and after outputting the output current of the first level, the inverter 420 outputs the output current of the second level different from the first level (S922).

[0192] For example, the second level can be a level higher than the first level.

[0193] Then, the control section 170 or the inverter control section 430 controls so that, during the second period in the switching device check mode, the winding of the motor 230 is in the second wiring state according to the operation of the switching device 450, and the inverter 420 outputs the output current of the first level (S930).

[0194] Next, the control section 170 or the inverter control section 430 controls so that, during the second period, the winding of the motor 230 is in the second wiring state according to the operation of the switching device 450, and after outputting the output current of the first level, the inverter 420 outputs the output current of the second level different from the first level (S932).

[0195] The first level and the second level in the second wiring state can be respectively the same levels as the first level and the second level in the first wiring state.

[0196] Then, the control section 170 or the inverter control section 430 determines whether the switching device 450 has abnormal operation based on the winding resistance of the motor 230 in the first wiring and the winding resistance of the motor 230 in the second wiring (S940).

[0197] For example, the control section 170 or the inverter control section 430 can calculate the first winding resistance of the motor 230 based on the output voltage Lvm3 detected according to the output of the output current of the first level Lvm1 during the first period Pm1 and the output voltage Lvm4 detected according to the output of the output current of the second level Lvm2, can calculate the second winding resistance of the motor 230 based on the output voltage Lvm5 detected according to the output of the output current of the first level Lvm1 during the second period Pm2 and the output voltage Lvm6 detected according to the output of the output current of the second level Lvm2, and can determine whether the switching device 450 has abnormal operation based on the first winding resistance and the second winding resistance. Thereby, it is possible to easily determine whether the switching device 450 for changing the wiring of the motor 230 has abnormality.

[0198] Specifically, the control section 170 or the inverter control section 430 can calculate the ratio of the first winding resistance and the second winding resistance and determine whether the switching device 450 is operating abnormally based on the calculated ratio. Thus, it is possible to easily determine whether the switching device 450 for switching the wiring of the motor 230 is operating abnormally.

[0199] On the other hand, the control section 170 or the inverter control section 430 can be controlled to calculate the ratio of the first winding resistance and the second winding resistance for each phase, determine that the switching device 450 is normal if the ratio of all the phases in the calculated ratio is within a prescribed range, and cause the switching device 450 to switch the winding of the motor 230 from the first wiring to the second wiring according to the operating frequency of the motor 230. Thus, it is possible to improve the power conversion efficiency or the motor 230 driving efficiency when the switching device 450 is operating normally.

[0200] Figures 10A to 14C is a diagram referred to when explaining the operation method of Figure 9A or Figure 9B is a diagram referred to when explaining the operation method of

[0201] First, Figure 10A is a diagram referred to when explaining the operation method of Figure 9A or

[0202] Referring to the drawings, Figure 10A (a) of illustrates the output current ina output from the inverter 420, particularly the phase current.

[0203] During the Pn1 period, the motor 230 is in the first wiring state by the operation of the switching device 450, and the inverter control section 430 can control the inverter 420 to output the output current of the first level Lvn1.

[0204] The Pns period after the Pn1 period is a period for switching from the first wiring to the second wiring, and no current can be output from the inverter 420.

[0205] On the other hand, unlike the drawing, during the Pns period, a current of a level lower than the output current of the first level Lvn1 can also be output. By outputting such an output current, as shown in the P2 period of Figure 8B , the speed of the motor 230 can be temporarily reduced.

[0206] Next, during the Pn2 period after the Pns period, the motor 230 is in the second wiring state by the operation of the switching device 450, and the inverter control section 430 can control the inverter 420 to output the output current of the first level Lvn1.

[0207] Figure 10A(b) shows an example of a switching voltage Sna corresponding to the output current ina output from the inverter 420 and an output voltage Snb as an effective voltage.

[0208] On the other hand, the output voltage Snb may correspond to a phase voltage.

[0209] Until the Tn1 time point that is the end time point of the Pn1 period, the pulse width of the switching voltage Sna rises and remains constant, and the output voltage rises and remains at the third level Lvn3.

[0210] During the Pns period after the Pn1 period, the output voltage becomes zero, and during the Pn2 period starting from the Tn2 time point after the Pns period, the pulse width of the switching voltage Sna rises and remains constant, and the output voltage rises and remains at the fourth level Lvn4 smaller than the third level Lvn3.

[0211] like Figure 10A As shown in (b), the control unit 170 or the inverter control unit 430 can calculate the first winding resistance under the first connection and the second winding resistance under the second connection based on the difference between the output voltage Snb under the first connection and the output voltage Snb under the second connection.

[0212] On the other hand, since the output current output from the inverter 420 is the same, when the switching device 450 operates normally, the first winding resistance having a higher level of the output voltage Snb is greater than the second winding resistance.

[0213] Based on this characteristic, the control unit 170 or the inverter control unit 430 can determine whether the switching device 450 has an operational abnormality.

[0214] On the other hand, Figure 10A In the example, one phase current ina is shown, but differently from this, the control unit 170 or the inverter control unit 430 can also control so that the u-phase current, v-phase current, and w-phase current at the output end of each phase of the inverter 420 have Figure 10A waveform.

[0215] The control unit 170 or the inverter control unit 430 may calculate the first winding resistance in the first connection and calculate the second winding resistance in the second connection using the relationship R=V / I.

[0216] At this time, if the ratio of the first winding resistance under the first connection to the second winding resistance under the second connection remains within a constant range, the control unit 170 or the inverter control unit 430 can be judged as normal. If it exceeds the constant range, it can be judged that the switching device 450 is abnormal.

[0217] In addition, the control section 170 or the inverter control section 430 can determine whether the switching device 450 is abnormal or normal depending on whether the first winding resistance under the first wiring is within the first range.

[0218] On the other hand, the control section 170 or the inverter control section 430 can also determine whether the switching device 450 is abnormal or normal depending on whether the second winding resistance under the second wiring is within the second range.

[0219] Next, Figure 10B is a diagram referred to when the operation method of Figure 9B is explained.

[0220] Referring to the drawings, Figure 10B (a) of FIG. 10 illustrates an output current ima output from the inverter 420, particularly a phase current.

[0221] During a Pm1a period in the Pm1 period, the motor 230 is in the first wiring state by the action of the switching device 450, and the inverter control section 430 can control the inverter 420 to output an output current of a first level Lvm1.

[0222] Next, during a Pm1b period in the Pm1 period, the motor 230 is in the first wiring state by the action of the switching device 450, and the inverter control section 430 can control the inverter 420 to output an output current of a second level Lvm2 larger than the first level Lvm1.

[0223] A Pms period after the Pm1 period, which is an interval of transition from the first wiring to the second wiring, can not output a current from the inverter 420.

[0224] On the other hand, unlike the drawing, during the Pms period, a current of a level lower than the output current of the first level Lvm1 can also be output. By outputting such an output current, as shown in a P2 period of Figure 8B , the speed of the motor 230 can be temporarily reduced.

[0225] Next, during a Pm2a period in a Pm2 period after the Pms period, the motor 230 is in the second wiring state by the action of the switching device 450, and the inverter control section 430 can control the inverter 420 to output an output current of the first level Lvm1.

[0226] Then, during a Pm2b period in the Pm2 period, the motor 230 is in the second wiring state by the action of the switching device 450, and the inverter control section 430 can control the inverter 420 to output an output current of a second level Lvm2 larger than the first level Lvm1.

[0227] Figure 10B (b) illustrates a switching voltage Sma corresponding to an output current ima output from the inverter 420 and an output voltage Smb as an effective voltage.

[0228] On the other hand, the output voltage Smb can correspond to a phase voltage.

[0229] During a Pm1a period in the Pm1 period, the pulse width of the switching voltage Sma rises and then remains constant, and the output voltage rises and then remains at a third level Lvm3, and during a Pm1b period in the Pm1 period, the pulse width of the switching voltage Sma rises and then remains constant again, and the output voltage rises and then remains at a fourth level Lvm4.

[0230] During a Pms period after the Pm1 period, the output voltage becomes zero.

[0231] During a Pm2a period in a Pm2 period after a Tm2 time point, the pulse width of the switching voltage Sma rises and then remains constant, and the output voltage rises and then remains at a fifth level Lvm5, and during a Pm2b period in the Pm2 period, the pulse width of the switching voltage Sma rises and then remains constant again, and the output voltage rises and then remains at a sixth level Lvm6.

[0232] At this time, the fifth level Lvm5 can be smaller than the third level Lvm3, and the sixth level Lvm6 can be smaller than the fourth level Lvm4.

[0233] Figure 10B As shown in (b) of FIG. 17, the control section 170 or the inverter control section 430 can calculate the first winding resistance under the first wiring and can calculate the second winding resistance under the second wiring, according to a difference between the output voltage Smb under the first wiring and the output voltage Smb under the second wiring.

[0234] In comparison with Figure 10A various levels of output currents can be output, and based on this, the winding resistance is calculated, so that the correctness of the calculated winding resistance can be further improved.

[0235] In particular, in comparison with Figure 10A various levels of output currents are output, so that the influence generated by components other than the stator resistance can be eliminated, as a result, the correctness of the calculated winding resistance can be further improved.

[0236] On the other hand, since the output currents output from the inverter 420 are the same, when the operation of the switching device 450 is normal, the first winding resistance having a level of a larger output voltage Smb is greater than the second winding resistance.

[0237] Based on this characteristic, the control section 170 or the inverter control section 430 can determine whether the switching device 450 has an abnormality in operation.

[0238] On the other hand, in Figure 10B , one phase current ima is exemplified, but unlike this, the control section 170 or the inverter control section 430 can also be controlled so that the u-phase current, the v-phase current, and the w-phase current, which are the output terminals of each phase of the inverter 420, respectively have Figure 10B waveforms in this order.

[0239] Figure 11 is a diagram showing a simplified equivalent circuit diagram of the motor under the first wiring and the second wiring.

[0240] Referring to the drawings, Figure 11 (a) of FIG. 23 is a diagram showing an equivalent circuit diagram of the motor 230 under the Y-wiring as the first wiring.

[0241] On the other hand, when a voltage Va is applied under the Y-wiring to control the current la, the stator winding becomes 3 / 2 Ra.

[0242] Next, Figure 11 (b) of FIG. 23 is a diagram showing an equivalent circuit diagram of the motor 230 under the Δ-wiring as the first wiring.

[0243] On the other hand, when the output current la is output under the Δ-wiring, Va is reduced to 1 / 3 times compared to the Y-wiring. The reason for this is that the winding resistance is reduced to 1 / 2 Ra.

[0244] Therefore, the control section 170 or the inverter control section 430 can determine whether the wiring is normally changed by the switching device 450 using this difference.

[0245] Figure 12A is a diagram exemplifying the output voltage detected as the phase current is sequentially applied with the first level and the second level under the first wiring and the second wiring.

[0246] Referring to the drawings, Figure 12A the Poa period of FIG. 24 exemplifies the U-phase output voltage during the Poa1 period, the V-phase output voltage during the Poa2 period, and the W-phase output voltage during the Poa3 period when the U-phase output current, the V-phase output current, and the W-phase output current, which output the first level Lvm1 and the second level Lvm2 under the first wiring, are output.

[0247] As shown in the diagram, the U-phase output voltage during the Poa period, the V-phase output voltage during the Poa period, and the W-phase output voltage during the Poa period can each have two voltage levels.

[0248] The control section 170 or the inverter control section 430 can calculate the first winding resistance of each phase U, V, W based on the phase U, V, W output current of the first level Lvm1 and the second level Lvm2 under the first wiring and the phase U, V, W output voltage.

[0249] Next, Figure 12A The Pob period of the Pob period of the U phase output voltage during the Pob1 period when the U phase output current, the V phase output current, and the W phase output current of the first level Lvm1 and the second level Lvm2 are output under the second wiring, the V phase output voltage during the Pob2 period, and the W phase output voltage during the Pob3 period are illustrated.

[0250] As illustrated, the U phase output voltage during the Pob period, the V phase output voltage during the Pob period, and the W phase output voltage during the Pob period can each have two voltage levels.

[0251] The control section 170 or the inverter control section 430 can calculate the second winding resistance of each phase U, V, W based on the phase U, V, W output current of the first level Lvm1 and the second level Lvm2 under the second wiring and the phase U, V, W output voltage.

[0252] Also, the control section 170 or the inverter control section 430 can determine whether the switching device 450 is abnormal based on the first winding resistance of each phase U, V, W and the second winding resistance of each phase U, V, W.

[0253] Figure 12B is a graph illustrating the first winding resistance of each phase U, V, W, the second winding resistance of each phase U, V, W, and the ratio thereof when the switching device 450 is normally operating.

[0254] Referring to the drawings, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring can be 0.96, 0.96, and 0.97 Ω, respectively.

[0255] On the other hand, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase can each correspond to the winding resistance corresponding to the a phase winding CA, the winding resistance corresponding to the b phase winding CB, and the winding resistance corresponding to the c phase winding CC, respectively. Figure 7

[0256] On the other hand, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring can be 0.41, 0.42, and 0.42 Ω, respectively.

[0257] ​In relation to this, the winding resistance ratio of the U-phase, the winding resistance ratio of the V-phase, and the winding resistance ratio of the W-phase, which are ratios of the winding resistance under the first wiring to the winding resistance under the second wiring, can be 2.3, 2.3, 2.3, respectively.

[0258] That is, in the case where the switching device 450 normally operates, preferably, a first range, which is a normal range of the winding resistance under the first wiring, is approximately 0.7 to 1.2 Ω, a second range, which is a normal range of the winding resistance under the second wiring, is approximately 0.3 to 0.6 Ω, and a third range, which is a normal range of the winding resistance ratio of the first wiring to the winding resistance ratio of the second wiring, is approximately 2.0 to 2.5.

[0259] The control unit 170 or the inverter control unit 430 can determine whether the switching device 450 is abnormal based on the data described above. Figure 12B

[0260] For example, the control unit 170 or the inverter control unit 430 can be controlled to calculate the ratio of the first winding resistance to the second winding resistance for each phase U, V, and W, and determine that the switching device 450 is abnormal and cause the winding of the motor 230 to operate in one of the first wiring or the second wiring in the case where the ratio of at least one of the calculated ratios exceeds a prescribed range. As described above, when the switching device 450 is abnormal, the motor 230 can be caused to perform emergency operation by being caused to operate in only one of the wiring states.

[0261] On the other hand, the control unit 170 or the inverter control unit 430 can be controlled to calculate the first winding resistance and the second winding resistance for each phase U, V, and W, and determine that the motor 230 is malfunctioning in the case where the range of the first winding resistance for each phase U, V, and W exceeds the first range and the range of the second winding resistance for each phase U, V, and W exceeds the second range. Thus, it is possible to easily determine whether the motor 230 is malfunctioning.

[0262] On the other hand, the control unit 170 or the inverter control unit 430 can be controlled to calculate the first winding resistance and the second winding resistance for each phase U, V, and W, and determine that the switching device 450 is normal and cause the switching device 450 to change the winding of the motor 230 from the first wiring to the second wiring in accordance with the frequency of operation of the motor 230 in the case where the range of the first winding resistance for each phase U, V, and W is within the first range and the range of the second winding resistance for each phase U, V, and W is within the second range. Thus, it is possible to improve the power conversion efficiency or the motor 230 drive efficiency when the switching device 450 normally operates.

[0263] ​On the other hand, the control section 170 or the inverter control section 430 can be controlled to calculate the first winding resistance and the second winding resistance for each phase U, V, W, determine that the switching device 450 is abnormal when the range of the first winding resistance of each phase U, V, W is within the first range and the range of the second winding resistance of each phase U, V, W exceeds the second range, and make the winding of the motor 230 act only in the first wiring. As described above, when the switching device 450 is abnormal, it is possible to make the motor 230 perform emergency operation by making it act only in one wiring state.

[0264] On the other hand, the control section 170 or the inverter control section 430 can be controlled to calculate the first winding resistance and the second winding resistance for each phase U, V, W, determine that the switching device 450 is abnormal when the range of the first winding resistance of each phase U, V, W exceeds the first range and the range of the second winding resistance of each phase U, V, W is within the second range, and make the winding of the motor 230 act only in the second wiring. As described above, when the switching device 450 is abnormal, it is possible to make the motor 230 perform emergency operation by making it act only in one wiring state.

[0265] Figures 13A to 13C is a graph showing the first winding resistance of each phase U, V, W, the second winding resistance of each phase U, V, W, and their ratio at the time of switching from the first wiring to the second wiring.

[0266] First, Figure 13A (a) of FIG. 1 illustrates an equivalent circuit diagram of the motor 230 when one relay in the switching device 450 abnormally operates.

[0267] Next, Figure 13A (b) of FIG. 1 is a graph showing Figure 13A (a) of FIG. 1 in the case of the first winding resistance of each phase U, V, W, the second winding resistance of each phase U, V, W, and their ratio.

[0268] Referring to the drawings, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring can be 0.97, 0.97, 0.97 Ω, respectively.

[0269] On the other hand, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring can be 0.71, 0.41, 0.72 Ω, respectively.

[0270] In relation thereto, the winding resistance ratio of the U phase, the winding resistance ratio of the V phase, and the winding resistance ratio of the W phase, which are the ratio of the winding resistance under the first wiring to the winding resistance under the second wiring, can be 1.4, 2.4, 1.4, respectively.

[0271] Since the winding resistance ratio of the first wiring to the second wiring is within the third range as a normal range only for the V phase, the control section 170 or the inverter control section 430 can determine that only the resistance ratio of the V phase is normal, and the resistance ratios of the U phase and the W phase are abnormal.

[0272] On the other hand, since the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring are within the first range as a normal range, the control section 170 or the inverter control section 430 can determine that the operation under the first wiring is normal.

[0273] On the other hand, since the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring are within the second range as a normal range only for the V phase, and the U phase and the W phase exceed the second range, the control section 170 or the inverter control section 430 can determine that the operation under the second wiring is abnormal.

[0274] Thus, the control section 170 or the inverter control section 430 can control so that, in the case of (a) of Figure 13A the switching device 450 operates only with the first wiring, not with the second wiring.

[0275] Figure 13B (a) of the motor 230 when two relays in the switching device 450 are abnormally operated.

[0276] Next, Figure 13B (b) of the motor 230 when two relays in the switching device 450 are abnormally operated. Figure 13B (a) of the motor 230 when two relays in the switching device 450 are abnormally operated.

[0277] Referring to the drawings, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring can be 0.89, 0.89, and 0.90 Ω, respectively.

[0278] On the other hand, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring can be 1.20, 0.47, and 0.64 Ω, respectively.

[0279] In relation thereto, the winding resistance ratio of the U phase, the winding resistance ratio of the V phase, and the winding resistance ratio of the W phase as the ratio of the winding resistance under the first wiring to the winding resistance under the second wiring can be 0.7, 1.9, and 1.4, respectively.

[0280] Since the winding resistance ratio of the first wiring to the second wiring exceeds the third range as a normal range in all phases, the control section 170 or the inverter control section 430 can determine that the switching device 450 is abnormal.

[0281] On the other hand, since the winding resistance of phase U, phase V, and phase W under the first connection are all within the first range which is the normal range, the control unit 170 or the inverter control unit 430 can determine that the operation under the first connection is normal.

[0282] On the other hand, since only the V-phase among the winding resistance of the U-phase, the V-phase, and the W-phase under the second connection is within the second range which is the normal range, while the U-phase and the W-phase are outside the second range, the control unit 170 or the inverter control unit 430 can determine that the operation under the second connection is abnormal.

[0283] Thus, the control unit 170 or the inverter control unit 430 can control the inverter to Figure 13B In the case of (a), the control switching device 450 operates only with the first connection, and does not operate with the second connection.

[0284] Figure 13C (a) shows an equivalent circuit diagram of the motor 230 when three relays in the switching device 450 operate abnormally.

[0285] then, Figure 13C (b) shows Figure 13C FIG. 1 is a diagram showing the first winding resistance in the case of (a), the second winding resistance of each phase U, V, and W, and their ratio.

[0286] Referring to the accompanying drawings, the winding resistance of the U-phase, the winding resistance of the V-phase, and the winding resistance of the W-phase in the first connection may be 0.97Ω, 0.97Ω, and 0.97Ω, respectively.

[0287] On the other hand, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase in the second connection can be 0.96, 0.98, and 0.97Ω, respectively.

[0288] In this regard, the U-phase winding resistance ratio, the V-phase winding resistance ratio, and the W-phase winding resistance ratio, which are ratios of the winding resistance in the first connection to the winding resistance in the second connection, may be 1.0, 0.99, and 1.0, respectively.

[0289] Since the winding resistance ratio of the first connection to the second connection exceeds the third range, which is a normal range, in all phases, the control unit 170 or the inverter control unit 430 may determine that the switching device 450 is abnormal.

[0290] On the other hand, since the winding resistance of phase U, phase V, and phase W under the first connection are all within the first range which is the normal range, the control unit 170 or the inverter control unit 430 can determine that the operation under the first connection is normal.

[0291] On the other hand, since the winding resistance of phase U, phase V, and phase W under the second connection all exceed the second range which is the normal range, the control unit 170 or the inverter control unit 430 can determine that the operation under the second connection is abnormal.

[0292] Thus, the control unit 170 or the inverter control unit 430 can control the inverter to Figure 13C In the case of (a), the control switching device 450 operates only with the first connection, and does not operate with the second connection.

[0293] Figures 14A to 14C 1 is a diagram showing the first winding resistance of each phase U, V, and W, the second winding resistance of each phase U, V, and W, and the ratio thereof when switching from the second connection to the second connection.

[0294] first, Figure 14A (a) shows an equivalent circuit diagram of the motor 230 when one relay in the switching device 450 operates abnormally.

[0295] then, Figure 14A (b) shows Figure 14A FIG. 1 is a diagram showing the first winding resistance in the case of (a), the second winding resistance of each phase U, V, and W, and their ratio.

[0296] Referring to the accompanying drawings, the winding resistance of the U-phase, the winding resistance of the V-phase, and the winding resistance of the W-phase in the first connection may be 1.23Ω, 0.48Ω, and 0.67Ω, respectively.

[0297] On the other hand, in the second connection, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase can be 0.40, 0.40, and 0.40 Ω, respectively.

[0298] In this regard, the U-phase winding resistance ratio, the V-phase winding resistance ratio, and the W-phase winding resistance ratio, which are ratios of the winding resistance in the first connection to the winding resistance in the second connection, may be 3.1, 1.2, and 1.7, respectively.

[0299] Since the winding resistance ratio of the first connection to the second connection exceeds the third range, which is a normal range, in all phases, the control unit 170 or the inverter control unit 430 may determine that the switching device 450 is abnormal.

[0300] On the other hand, since the winding resistance of phase U, phase V, and phase W under the first connection all exceed the first range which is the normal range, the control unit 170 or the inverter control unit 430 can determine that the operation under the first connection is abnormal.

[0301] On the other hand, since the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring are all within the second range as the normal range, the control section 170 or the inverter control section 430 can determine that the operation under the second wiring is normal.

[0302] Thereby, the control section 170 or the inverter control section 430 can control so that, in the case of (a) of FIG. 10, Figure 14A In the case of (a) of FIG. 10, the control section 170 or the inverter control section 430 can control the switching device 450 to operate only under the second wiring, not under the first wiring.

[0303] Figure 14B The (a) of FIG. 10 illustrates an equivalent circuit diagram of the motor 230 when two relays in the switching device 450 are abnormally operated.

[0304] Next, Figure 14B The (b) of FIG. 10 is a graph showing the first winding resistance, the second winding resistance of each phase U, V, W, and the ratio thereof in the case of (a) of FIG. 10. Figure 14B

[0305] Referring to the drawings, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring can be 0.68, 0.68, 0.41 Ω, respectively.

[0306] On the other hand, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring can be 0.4, 0.4, 0.41 Ω, respectively.

[0307] In relation thereto, the winding resistance ratio of the U phase, the winding resistance ratio of the V phase, and the winding resistance ratio of the W phase as the ratio of the winding resistance under the first wiring to the winding resistance under the second wiring can be 1.7, 1.7, 1.0, respectively.

[0308] Since the winding resistance ratio of the first wiring to the second wiring exceeds the third range as the normal range in all phases, the control section 170 or the inverter control section 430 can determine that the switching device 450 is abnormal.

[0309] On the other hand, since the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring all exceed the first range as the normal range, the control section 170 or the inverter control section 430 can determine that the operation under the first wiring is abnormal.

[0310] On the other hand, since the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring are all within the second range as the normal range, the control section 170 or the inverter control section 430 can determine that the operation under the second wiring is normal.

[0311] ​Thus, the control section 170 or the inverter control section 430 can be controlled to control the switching device 450 to act only with the second wiring, not with the first wiring, in the case of (a) of FIG. 10. Figure 14B

[0312] Figure 14C FIG. 11 is a diagram illustrating an equivalent circuit of the motor 230 when the three relays in the switching device 450 abnormally act, in the case of (a) of FIG. 10.

[0313] Next, Figure 14C FIG. 12 is a diagram illustrating the first winding resistance, the second winding resistance of each phase U, V, W, and the ratio thereof, in the case of (b) of FIG. 10. Figure 14C

[0314] Referring to the drawings, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring can be 0.39, 0.41, 0.41 Ω, respectively.

[0315] On the other hand, the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring can be 0.4, 0.4, 0.41 Ω, respectively.

[0316] In relation thereto, the winding resistance ratio of the U phase, the winding resistance ratio of the V phase, and the winding resistance ratio of the W phase as the ratio of the winding resistance under the first wiring to the winding resistance under the second wiring can be 0.98, 1.0, 1.0, respectively.

[0317] Since the winding resistance ratio under the first wiring to the winding resistance under the second wiring exceeds the third range as a normal range in all phases, the control section 170 or the inverter control section 430 can determine that the switching device 450 is abnormal.

[0318] On the other hand, since the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the first wiring all exceed the first range as a normal range, the control section 170 or the inverter control section 430 can determine that the action under the first wiring is abnormal.

[0319] On the other hand, since the winding resistance of the U phase, the winding resistance of the V phase, and the winding resistance of the W phase under the second wiring all fall within the second range as a normal range, the control section 170 or the inverter control section 430 can determine that the action under the second wiring is normal.

[0320] Thus, the control section 170 or the inverter control section 430 can be controlled to control the switching device 450 to act only with the second wiring, not with the first wiring, in the case of (a) of FIG. 10. Figure 14C

[0321] Figure 15 ​​​is a flowchart showing a method of operation of the motor drive device according to another embodiment of the present application, Figures 16A to 16C is a flowchart showing a method of operation of the motor drive device according to another embodiment of the present application, Figure 15 is a flowchart showing a method of operation of the motor drive device according to another embodiment of the present application.

[0322] Reference is made to Figure 15 , Figure 15 The method of operation of the motor drive device according to another embodiment of the present application is similar to the method of operation of the motor drive device according to the embodiment described above, but differs in that, after the step S930, the steps S950 to S965 are further executed. Figure 9A Reference is made to the description of

[0323] with regard to the steps S910, S920, and S930. Figure 9A

[0324] On the other hand, in the drawings, only the steps S910, S920, and S930 are shown, but the present application is not limited thereto, and after the steps S910, S920, S922, S930, and S932 of the motor drive device according to the embodiment described above are executed, the step S950 can be further executed. Figure 9B

[0325] On the other hand, the control unit 170 or the inverter control unit 430 calculates the first winding resistance under the first connection and the second winding resistance under the second connection. In particular, the first winding resistance under the first connection and the second winding resistance under the second connection can be calculated for each of the phases U, V, and W.

[0326] Next, the control unit 170 or the inverter control unit 430 determines whether the first winding resistance is within the first range and whether the second winding resistance is within the second range (S950).

[0327] As described above, as an example, the first range can be 0.7 to 1.2, and the second range can be 0.3 to 0.6.

[0328] Then, the control unit 170 or the inverter control unit 430 can control so that, in a case where the first winding resistance is within the first range and the second winding resistance is within the second range, the switching device 450 changes the winding of the motor 230 from the first connection to the second connection in accordance with the operating frequency of the motor 230 (S952).

[0329] Thereby, the power conversion efficiency or the motor 230 driving efficiency can be improved when the switching device 450 normally operates.

[0330] ​​On the other hand, the control section 170 or the inverter control section 430 can be controlled so as to cause the motor 230 to continue to operate without stopping during the switching of the winding of the motor 230 from the first connection to the second connection by the switching device 450. As described above, since the motor 230 does not stop when the switching device 450 performs the switching operation, the operation efficiency of the motor 230 can be improved.

[0331] On the other hand, the control section 170 or the inverter control section 430 can be controlled so as to cause the motor 230 to continue to operate without stopping during the switching of the winding of the motor 230 from the first connection to the second connection by the switching device 450. As described above, since the motor 230 does not stop when the switching device 450 performs the switching operation, the operation efficiency of the motor 230 can be improved.

[0332] On the other hand, in a case where the step S950 is not satisfied, the control section 170 or the inverter control section 430 determines whether the first winding resistance is within the first range and whether the second winding resistance exceeds the second range (S955).

[0333] Also, the control section 170 or the inverter control section 430 can be controlled so as to cause the switching device 450 to operate only with the first connection and not with the second connection in a case where the first winding resistance is within the first range and the second winding resistance exceeds the second range (S957). As described above, when the switching device 450 is abnormal, by causing it to operate only in one connection state, the motor 230 can be caused to operate in an emergency.

[0334] On the other hand, in a case where the step S955 is not satisfied, the control section 170 or the inverter control section 430 determines whether the first winding resistance exceeds the first range and whether the second winding resistance is within the second range (S960).

[0335] Also, the control section 170 or the inverter control section 430 can be controlled so as to cause the switching device 450 to operate only with the second connection and not with the first connection in a case where the first winding resistance exceeds the first range and the second winding resistance is within the second range (S957). As described above, when the switching device 450 is abnormal, by causing it to operate only in one connection state, the motor 230 can be caused to operate in an emergency.

[0336] On the other hand, in a case where the step S960 is not satisfied, the control section 170 or the inverter control section 430 can determine that the first winding resistance exceeds the first range and the second winding resistance exceeds the second range, and can determine that the motor 230 has failed (S965). Thereby, it can be easily determined whether the motor 230 has failed.

[0337] In addition, when the motor 230 malfunctions, the control section 170 or the inverter control section 430 not only stops the operation of the motor 230, but also stops the operation of the inverter 420 and the like, so that the circuit elements in the motor drive device 220 can be prevented from being damaged and the like.

[0338] Figure 16A Examples of the equivalent circuit diagram of the motor 230 when the first winding resistance is within the first range and the second winding resistance is within the second range are illustrated.

[0339] Figure 16A (a) of FIG. 9 illustrates an equivalent circuit diagram of the motor 230 as the first connection of Y connection, Figure 16A (b) of FIG. 9 illustrates an equivalent circuit diagram of the motor 230 as the second connection of Δ connection.

[0340] As Figure 15 Step S952 in FIG. 9, the control section 170 or the inverter control section 430 can be controlled to switch between the first connection and the second connection in accordance with the operating frequency of the motor 230.

[0341] Figure 16B Examples of the equivalent circuit diagram of the motor 230 when the first winding resistance is within the first range and the second winding resistance exceeds the second range are illustrated.

[0342] Figure 16B (a) of FIG. 10 illustrates a case corresponding to the abnormality of three relay elements, as shown in Figure 13C (b) of FIG. 10 illustrates a case corresponding to the abnormality of two relay elements, as shown in Figure 16B (c) of FIG. 10 illustrates a case corresponding to the abnormality of one relay element, as shown in Figure 13B Figure 16B Figure 13A Thus, in the case of , the control section 170 or the inverter control section 430 can be controlled to cause the switching device 450 to operate only with the first connection and not with the second connection.

[0343] Figure 16B Examples of the equivalent circuit diagram of the motor 230 when the first winding resistance exceeds the first range and the second winding resistance is within the second range are illustrated.

[0344] Figure 16C (a) of FIG. 11 illustrates a case corresponding to the abnormality of three relay elements, as shown in

[0345] (b) of FIG. 11 illustrates a case corresponding to the abnormality of two relay elements, as shown in Figure 16C (c) of FIG. 11 illustrates a case corresponding to the abnormality of one relay element, as shown in Figure 13C Figure 16C Figure 13B Figure 16C Figure 13A ​​​​​As shown, this corresponds to a situation where one relay element is abnormal.

[0346] Therefore, in Figure 16C In this case, the control unit 170 or the inverter control unit 430 may control the switching device 450 so that it operates only in the second wiring and does not operate in the first wiring.

[0347] On the other hand, in addition to Figure 1 In addition to the air conditioner 100, Figures 4 to 16C The motor drive device 220 of the embodiment of the present invention described above can also be applied to various household appliances. For example, it can be applied to various fields such as laundry processing equipment (washing machines, dryers, etc.), refrigerators, water purifiers, sweeping robots, robots, vehicles, and drones.

[0348] On the other hand, the operating method of the motor drive device or air conditioner of the present invention can be implemented by a processor-readable code in a processor-readable recording medium provided in the motor drive device or air conditioner. Processor-readable recording media include all types of recording devices that store data readable by a processor. Examples of processor-readable recording media include ROM, RAM, CD-ROM, magnetic disk, floppy disk, optical data storage device, etc., and also include recording media implemented in the form of carrier waves such as transmission via the Internet. In addition, the processor-readable recording medium is distributed on computer systems connected via a network, so that the processor-readable code can be stored and executed in a distributed manner.

[0349] Furthermore, the preferred embodiments of the present invention are illustrated and described above, but the present invention is not limited to the specific embodiments described above. Without departing from the technical concept of the present invention, ordinary technicians in the technical field to which the present invention belongs can perform various modified implementations thereof, and such modified implementations should not be understood separately from the technical concept or prospects of the present invention.

Claims

1. A motor drive apparatus characterized by comprising: Comprising: an inverter provided with a plurality of switching elements, which outputs an alternating-current power to a motor based on switching operations; a switching device configured between the inverter and the motor, which changes a winding of the motor to a first connection or a second connection; an output current detection section for detecting an output current output from the inverter; a control section which controls the inverter and the switching device; and an output voltage detection section for detecting an output voltage output from the inverter, in the switching device check mode, during a first period, the winding of the motor is in a state of the first connection according to the operation of the switching device, a first-level output current and a second-level output current greater than the first-level output current are sequentially output from the inverter, during a second period after the first period, the winding of the motor is in a state of the second connection according to the operation of the switching device, the first-level output current and the second-level output current are sequentially output from the inverter, during a third period between the first period and the second period, a third-level output current less than the first-level output current is output from the inverter, the control section calculates a first winding resistance of the motor based on a first output voltage detected according to the output of the first-level output current during the first period, the control section calculates a second winding resistance of the motor based on a second output voltage detected according to the output of the first-level output current during the second period, the control section determines whether the switching device has an abnormal operation based on the first winding resistance and the second winding resistance.

2. The motor drive device according to claim 1, wherein the control section calculates a ratio of the first winding resistance and the second winding resistance for each phase, and determines that the switching device is normal when the ratio of all of the phases of the calculated ratio is within a prescribed range, the control section controls so that the switching device changes the winding of the motor from the first connection to the second connection according to an operation frequency of the motor.

3. The motor drive device according to claim 2, wherein the control section controls so that the operation frequency of the motor is decreased from a first frequency to a second frequency and then increased again during the period in which the switching device changes the winding of the motor from the first connection to the second connection.

4. The motor drive device according to claim 1, wherein the control section calculates a ratio of the first winding resistance and the second winding resistance for each phase, and determines that the switching device is abnormal when the ratio of at least one of the phases of the calculated ratio is outside a prescribed range, the control section controls so that the winding of the motor is operated only in one of the first connection and the second connection.

5. The motor drive device according to claim 1, wherein the control section calculates the first winding resistance and the second winding resistance for each phase, ​ When the range of the first winding resistance of each phase exceeds the first range and the range of the second winding resistance of each phase exceeds the second range, the control section determines that the motor is malfunctioning.

6. The motor drive device according to claim 1, wherein the control section calculates the first winding resistance and the second winding resistance for each phase, When the range of the first winding resistance of each phase is within the first range and the range of the second winding resistance of each phase is within the second range, the control section determines that the switching device is normal, and controls the switching device to change the winding of the motor from the first connection to the second connection according to the operating frequency of the motor, When the range of the first winding resistance of each phase is within the first range and the range of the second winding resistance of each phase exceeds the second range, the control section determines that the switching device is abnormal, and controls the winding of the motor to operate only with the first connection, When the range of the first winding resistance of each phase exceeds the first range and the range of the second winding resistance of each phase is within the second range, the control section determines that the switching device is abnormal, and controls the winding of the motor to operate only with the second connection.

7. An air conditioner, comprising the motor drive device according to any one of claims 1 to 6.

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